Weekend Hail Storm

What a weekend of damaging hail. The pictures and video tell the story.

Here’s a slide show of photos from wcnc.com.

Photo from Dan Poche

Hail like this is very rare in the Carolinas especially over such a large area. The thunderstorms that produced this hail were between 45-50,000’ tall and had freezing heights were around 9-10′,000’. The key to getting such large hail were the rotating updrafts, which classified them as supercells. These same rotating updrafts called mesocyclones can lead to tornadoes, but only one touched down. These rotating updrafts I estimated to be around 70-80 mph. The hail stones themselves had terminal velocities of between 60-80mph for the golf ball size hail and between 80-100mph for the baseball size hail. These are just estimated based on a perfect sphere, as you can see most were odd shapes due to collisions with other hail stones and raindrops.

Measurement                       Updraft Speed
in.cm.              mph            m/s
bb< 1/4< 0.64< 24< 11
pea1/40.642411
marble1/21.33516
dime7/101.83817
penny3/41.94018
nickel7/82.24621
quarter12.54922
half dollar1 1/43.25424
walnut1 1/23.86027
golf ball1 3/44.46429
hen egg25.16931
tennis ball2 1/26.47734
baseball2 3/47.08136
tea cup37.68438
grapefruit410.19844
softball4 1/211.410346

How hail forms (Courtesy Jetstream NOAA)

hail1hail2

You can see how many times the hail circulated based on the rings inside the hail stone. These are from Fort Mill.

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If you had damage here’s a complete list of all the official reports if you need them for insurances purposes. Here’s a link to the PDF.